Discrimination of midday jird's odour by house mice

Responses of three groups of house mice, Mus musculus, of different origins (feral mice, commensal mice and third-generation mice of a laboratory colony from feral parents) to the odour of midday jirds, Meriones meridianus, were studied to examine the role of odour in spatial segregation of these species. Mice that co-habited with jirds avoided the jirds' odour, whereas commensal mice and laboratory-bred mice were indifferent to the jirds' odour. Experiments supported the hypotheses that (1) odours mediate inter-species interactions and (2) intraspecific avoidance of rodents based on odour cue is learned rather than innate.